These motherboard refrigerators are hard to work on. Remove the cover from the motherboard and measure the voltage from the main 4 pin power connector, comp. pin, should be 115 volts to common white terminal. If not, you will need to check things per the South Jesey data sheet found in my article in the "sticky" GE GSS and PSS refrigerators.
You might have a intermittant power line or a bad encoder control in the fridg.